Hi there,
I bought the Tower Light - Red Yellow Green Alert Light with Buzzer - 12VDC PID: 2993.
I'm hooking it up to a raspberry pi zero using the following transistor circuit and GPIO pins:
https://learn.adafruit.com/rgb-led-strips/usage
On powering up the project some of the leds came on immediately, it was only until I started my python programme that they turned off and then sequentially turned on as per the programme design.
On a subsequent power up the leds have not turned on at all and the only output that seems to work is the buzzer.
I moved the buzzer onto all the other transistors and it works on all four proving the circuit is ok.
Finally, I connected each LED to 12v and they do not light up.
Is it possible I have blown the LEDs?
Should I have used a resistor in series with each LED between Vcc (12v) and the collector?
Below are the circuit connections, my only concern is that I connected a ground pin from the pizero to the ground of the 12v supply.
12v<--->BROWN LEAD><---><RED LEAD><--->COLLECTOR1>
12v<--->BROWN LEAD><---><GREEN LEAD><--->COLLECTOR2>
12v<--->BROWN LEAD><---><YELLOW LEAD><--->COLLECTOR3>
12v<--->BROWN LEAD><---><ORANGE(BUZZER) LEAD><--->COLLECTOR4>
12v <--->buck convertor><---><PiZero>
<PiZero> <---><GPIO39(GND)><---><GND of 12V supply> < Is this Okay to do?
<PiZero> <---><GPIO5><---><Resistor><---><BASE1>
<PiZero> <---><GPIO6><---><Resistor><---><BASE2>
<PiZero> <---><GPIO13><---><Resistor><---><BASE3>
<PiZero> <---><GPIO19><---><Resistor><---><BASE4>
Thanks,
Paul